Prevalent diseases of the eye; a reference handbook

Front matter

Class ~K £4 fa

Book .T~3

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Preface

Although most treatises upon diseases of the eye have been written ostensibly for the general practitioner and the medical student, they have been, with few exceptions, adapted in reality not to their needs, but to the requirements of the specialist in this department of medicine. A treatise upon the eye really intended to meet the needs of the general practitioner, it has seemed to the author, should take into account the fact that the great majority of physicians are not skilled in the use of the ophthalmoscope, and are not likely ever to be; that they possess neither the experience nor the necessary paraphernalia to make trustworthy tests of refractive errors, of muscular anomalies, or of the visual fields; and that they are not qualified to perform, and have no desire to undertake, the more delicate eye operations. It should recognize, further, that because of these limitations the general practitioner is hopelessly handicapped as regards the diagnosis, and consequently the treatment, of many important eye affections; but, on the other hand, that there are other important affections of the eye which he is competent, or should be competent, to diagnosticate correctly, and to treat successfully.

It should, therefore, devote especial attention to this latter class of maladies, and, particularly, should help him to discriminate between these cases and those

PREFACE which are without his province, so that, on the one hand, he may not send trivial affections, which he is himself competent to treat, to the distant specialist, or, on the other hand, lose precious time, and thus permit sight to become irreparably damaged, through attempting to cope with maladies which urgently demand the skill of the trained ophthalmologist.

Again, such a work should take into account that the general practitioner is most in need of definite information as to the more frequently encountered diseases of the eye, and, while these should be dwelt upon, that it is a work of supererogation, so far as he is concerned, to give space to the description of rare affections which, in all probability, he will never encounter. It should also make clear to him the sharp line to be drawn between those diseases of the eye in which delay in the employment of remedial measures is permissible, or even desirable, and those in the treatment of which time is an allimportant factor.

In offering suggestions as to treatment, it should be concise, unambiguous, and as specific as practicable, not giving a long list of remedies, and leaving the inexperienced reader to choose from among them, but recommending definitely what the author — if he is qualified to write such a book — should know, from his own observation, is best adapted to the condition under consideration. The simpler operations, which the general practitioner may perform, it should describe in detail; the more difficult ones, which he is not warranted in undertaking, need not be so described, though the indications for them should be clearly set forth.

For such a book — not a complete treatise upon diseases of the eye, but a concise description of the commoner ocular maladies — designed solely to meet the

PREFACE. Ill

needs of the physician engaged in general practice, the author is convinced there is a real want; and this want, with what measure of success it remains to be seen, he has endeavored to supply.

Having in mind the well-worn proverb, "a little knowledge is a dangerous thing," he has not thought it desirable to encourage the general practitioner to rely upon the ophthalmoscope as a means of diagnosis. Indeed, he has not even given a description of it, or explained its use. Furthermore, he has constantly assumed that the knowledge which it affords is not at the reader's command. For the same reason, he has not given a detailed account of the several methods of measuring the refractive and muscular anomalies of the eyes, of charting the visual fields, etc. On the other hand, especial pains have been taken to describe fully such aids to diagnosis (the examination by oblique illumination, for example) as can but prove helpful, and such therapeutic measures, operative and non-operative, as the general practitioner may employ with advantage. The hope is indulged that the introductory chapters upon "Diagnosis" and upon "Treatment" will prove of practical value.

For greatly appreciated advice and many helpful suggestions in connection with the preparation and publication of this work, the author takes pleasure in acknowledging his indebtedness to Dr. Wm. H. Welch and to Dr. Henry M. Hurd. He is also indebted to Dr. Albert H. Buck, editor of the "Reference Handbook of the Medical Sciences," for permission kindly accorded him to make free use, in writing Chapters V and VII, of the articles upon "Affections of the Conjunctiva" and upon "Iritis," which it was the author's privilege to contribute to that standard work.

IV PREFACE.

To Dr. A. Maitland Ramsay he is under obligation for permission to use several admirable illustrations from his "Atlas of External Diseases of the Eye."

SYNOPSIS OF CONTENTS.

Chapter I

General Observations upon the Diagnosis of Diseases of the Eye. Description of the Methods of Examining the Eye

Available to the General Practitioner _ 1 7-37

The difficulties in diagnosticating diseases of the eye with which the general practitioner has to contend, 17. Some of the errors into which he is apt to fall, 17. His skill in the use of the ophthalmoscope rarely such as to make it a trustworthy means of diagnosis, 19. Other methods of examining the eye, 19. Oblique illumination, 19. Value of the information which it affords, 21. Facility in its employment easily acquired, 2 1 . The assistance afforded by a transitory mydriatic, 21. Eversion of the eyelids, 22. Determination of intra-ocular tension, 23. The reactions of the pupil, 24. Variations in the size and reactions of the pupil in health and disease, 25. Determination of visual acuteness, 27. Simple method of measuring the visual field, 29. The patient's description of his symptoms often misleading, 31. Pertinent questions which he should be asked, 31. Significance of his replies, 31. Inspection of the eye by daylight, 34. The condition of the lids, lacrimal apparatus, conjunctiva, cornea, anterior chamber, iris, the appearance and behavior of the pupil, the tension of the globe, and the movements of the eyes, to be noted, 34. Loss of sensibility of the cornea — how determined, 35. Diagnostic significance of the different types of vascular injection of the eye, and of the character and amount of the discharge present, 35. Examination of the anterior structures of the eye by oblique illumination, with and without the application of a mydriatic, 36.

CHAPTER II. General Observations upon the Treatment of Diseases of

the Eye 38-62

A correct diagnosis having been reached the selection of the proper remedy to meet the condition usually not difficult, 38. Importance of constitutional remedies in the treatment of diseases of the eye, 38. The local and constitutional remedies especially useful in the treatment of eye diseases, 39. Indications for, and contraindications to, their use, and the methods of employing

I a SYNOPSIS OF CONTENTS.

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them, 39, 40. Importance of an early diagnosis, and the prompt employment of therapeutic measures, in many affections of the eye, 40. Transference of infectious material through the careless use of eye-droppers, 41. Cautions necessary in the employment of poisonous colly ria, 43. Colly ria as commonly prepared by the apothecary often contaminated, 43. Methods of applying collyria and ointments to the eye, 44. Mydriatics, 46. Atropin, the most valuable local remedy in the treatment of diseases of the eye, capable of doing much harm when injudiciously employed, 46. Possibility of its inducing glaucoma in persons beyond middle life, 47. Follicular conjunctivitis caused by its long-continued use, 48. Idiosyncrasies met with in individuals with reference to atropin and other mydriatics, 48. Myotics, 48. Indications for their employment, 48. Their mode of action in glaucoma, 48. Eserin the most valuable, 49. How it should be employed, 49. Contraindications to its use, 50. Astringent and antiseptic agents, 50. Useful especially in conjunctival affections, 50. Value of silver nitrate, protargol, and argyrol in the severer types of conjunctivitis, 51. The application of ■carbolic acid and tincture of iodin to corneal ulcers, 5 r . Cocain useful only as an anesthetic, 5 1 . Harmful when otherwise employed, 52. Causes desquamation of the corneal epithelium, and favors bacterial invasion, 52. Dionin a valuable analgesic and lymphagogue,52. Opium a valuable local remedy in ocular inflammations, 53. Method of employing it, 53. Ointments, their preparation and uses, 53. Castor-oil in burns of the eye and abrasions of the cornea, 54. Light not the reprehensible thing it was formerly supposed to be, 54. The application of heavy bandages to the eyes, designed to exclude it, and confinement in very dark rooms detrimental rather than helpful, 54. Inflamed and painful eyes, nevertheless, should be protected from undue exposure to light, 54. Method of examining and making applications to the eyes of children, 57. Constitutional remedies useful in the treatment of diseases of the eye, 57. The value, and indications for the employment, of mercury, potassium iodid, quinin, iron, strychnin, arsenic, sodium pyrophosphate, pilocarpin, etc., in diseases of the eye, 57-61. Efficacy of the antitoxin treatment in diphtheritic conjunctivitis, 61.

CHAPTER III. Diseases of the Eyelids and Orbit 63-117

Diseases of the Eyelids.

Blepharitis marginalis, 63. Commonly a chronic condition, 63. In children, eczematous in character, and usually due to malnutrition and disturbed digestion; in adults, to accommodative

SYNOPSIS OF CONTENTS. I b

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strain, 64. Treatment, 65 Hordeolum, 67. Etiology and treatment, 69. Eczema, 71. Constitutional and local causes, 71. General and local treatment, 71. Chalazion, 73. Etiology, 74. Often multiple, 74. Chronic blepharitis a predisposing cause, 74. Treatment, 74. Non-operative treatment seldom of avail, 74. Description of operation found most effectual and easiest of performance, 75. Milium, 77. Hydrocystoma, 78. Warts, 78. Malignant growths, 78. Tarsitis, 79. Commonly of syphilitic origin, 79. Entropion, 80. Spasmodic entropion, 81. May result from spasm of the orbicularis, commonly dependent upon photophobia, or from senile relaxation of the lid-structures, 81. Faulty construction of the tarsal cartilage or of the arrangement of the orbicularis a predisposing cause, 81. Organic entropion, 81. Produced by contraction of scar-tissue in or beneath the palpebral conjunctiva, 81. Usually consequent upon trachoma, 8r. Treatment of spasmodic and organic entropion, 81. Operative procedures indicated, 82. Correction of entropion of the lower lid by the production of an eschar with caustic potash, 82. Ectropion, 88. Like entropion, may be caused by spasm of the orbicularis, by contraction of scar tissue, or by senile relaxation of the lid-structures, 88. Spasmodic ectropion, 88. Etiology, 88. Organic ectropion, 89. May result from any lesion which leads to destruction of the external integument of the lid or neighboring parts, 89. Incomplete ectropion of the lower lid a not infrequent complication of disease of the lacrimal apparatus, 89. Non-operative and operative treatment of the different varieties of ectropion, 91. Snellen's operation for ectropion, 92. Value of Wolfe and Thiersch grafts in operations for the correction of ectropion, 97. Ptosis, 98. Occurs as a congenital and as an acquired fault, 98. Acquired ptosis, 98. Commonly due to paralysis of the third nerve, 98. Generally unilateral and of syphilitic origin, 98. Congenital ptosis, 98. Usually bilateral and caused by faulty innervation, or imperfect development or absence, of the levator muscle, 98. Treatment, 99. Only operative treatment of avail in congenital ptosis, 99. In acquired ptosis operative measures indicated only after other means have proved ineffectual, 99. Gruening's modification of Bowman's operation for ptosis, 102. Panas' operation, 104. Paralysis of the facial nerve, 105. Symptoms and consequences, 105. Etiology. 106. Treatment, 106.

Diseases of the Orbit.

Cellulitis of the orbit, 108. Acute and chronic forms of the affection, 108. Symptoms, 108. Etiology, 108. Fatal consequences from cerebral implication, 109. Treatment, 109. Periostitis, caries, and necrosis of the orbital -walls, in. Causes and conse-

SYNOPSIS OF CONTENTS.

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quences, in. Treatment, 112. Value of hydrochloric acid,

113. Tumors of the orbit, 113. Mode of origin, 113.

Varieties, 114. Consequences, 114. Diagnosis, 115. Treatment, 116.

CHAPTER IV. Diseases of the Lacrimal Apparatus __ 1 18-150

Diseases of the Lacrimal Gland.

Of infrequent occurrence, because of the protected position of the gland and its multiple system of ducts, 118. Dacryoadenitis, 119. Occurs as an acute and as a chronic affection, 118. Possible relationship to mumps, 119. Acute dacryoadenitis, 119. Chronic dacryoadenitis, 119. Treatment, 120. Fistula of the lacrimal gland, 120. Dacryops, 121. Dacryoliths, 122. Dislocation of the lacrimal gland, 122. Met with as a spontaneous condition and as a consequence of trauma, 122. Hypertrophy of the lacrimal gland, 123. Atrophy of the lacrimal gland, 124. Tumors of the lacrimal gland, 125. Are rare, and not infre-

Diseases of the Drainage Apparatus.

Of common occurrence, 125. Intimate pathological relationship between the drainage apparatus and the nasal passages, 125. Atresia of the lacrimal puncta, 126. Occurs as a congenital and as an acquired condition, 126. Treatment, 127. Malposition of the puncta, 128. Eversion of the puncta, 128. Inversion of the puncta, 128. Etiology and treatment, 128. Division of the canaliculus the efficient remedy, 128. Description of the operation, 128. Atresia of the canaliculi, 130. Dacryoliths, 131. Polypi, 131. Dacryocystitis, 131. Etiology, 131. Primary inflammation of the lacrimal sac, 131. Blennorrhea of the lacrimal sac, 132. Symptoms, 132. Mucocele, 132. Course of the disease, 132. Acute dacryocystitis, 133. Lacrimal fistula an occasional consequence, 134. Dacryocystitis rarely dependent upon ocular disease, 135. Treatment, 136. Prelacrimal abscess, 137. Stricture of the nasal duct, 137. Its etiology, 137. Symptoms and consequences, 138. Treatment, 140. The efficacy of thorough dilatation by means of probes large enough to restore the normal caliber of the duct, 140. Author's series of lacrimal probes, 141. Electrolysis, 149. Removal of the lacrimal gland, 149. Excision of the lacrimal sac and its destruction with the actual cautery, 149. Dacryocystitis and occlusion of the nasal duct in the new-born, 150.

CHAPTER V. page.

Diseases of the conjunctiva of common occurrence, 151. Importance of a correct diagnosis in dealing with them, 151. Signs and symptoms of inflammation of the conjunctiva, 151. Severe remedies, which cause pain and increase photophobia and lacrimation, rarely indicated, 152. Hyperemia of the conjunctiva, 152. Conjunctivitis, 154. Catarrhal conjunctivitis, 154. Purulent or gonorrheal conjunctivitis, 158. Ophthalmia neonatorum, 165. Croupous conjunctivitis, 168. Diphtheritic conjunctivitis, 169. Follicular conjunctivitis, 173. Trachomatous conjunctivitis, 1 74. Serious consequences to which it gives rise, 174. Vernal conjunctivitis, 183. Bulbar and palpebral types, 183. Phlyctenular conjunctivitis, 186. Of constitutional origin, 186. Toxic conjunctivitis, 192. Argyria conjunctivae, 193. Subconjunctival hemorrhage, 193. Pinguecula, 194. Pterygium, 195. Author's view of its etiology', 196. Pseudo-pterygium, 197. Operative treatment of pterygium, 198.

CHAPTER VI. Diseases of the Cornea and Sclera 202-245

Diseases of the Cornea.

Keratitis, 202. Divisible into suppurative and non-suppurative keratitis, 202. Suppurative keratitis, 204. Etiology, 204. Tractable and intractable types, 204. Phlyctenular keratitis, 205. Abscess and ulcer of the cornea, 207. Pathology, 207. Etiology, 210. Often of traumatic origin, 211. Treatment, local and constitutional, 211. Employment of carbolic acid, 213. Use of thermo-cautery, 214. Keratomalacia, 215. Neuropathic keratitis, 216. Herpes zoster ophthalmicus, 218. Post-malarial keratitis, 220. Dendritic keratitis, 220. Herpes cornece febrilis, 220. Non-suppurative keratitis, 233. Interstitial keratitis, 223. Always dependent upon inherited syphilis, 223. Obstinacy its chief characteristic, 225. Though ultimate prognosis good, 226. Treatment, 227. Pannitic keratitis, 231. Canthotomy in treatment of pannitic keratitis, 233. Opacities 0} the cornea, 235. Arcus senilis, 235. Nebulas, Maculce, Leucomata, 236. Leucoma adherens, 236. Staphyloma 0} the cornea, 239. Etiology, 238. May be partial or complete, 238. Conical cornea, 241. Attended by a high degree of myopia, 241.

Diseases of the Sclera.

The tough and non-vascular sclera not often the seat of disease, 242. Scleritis, 242. Acute, diffuse scleritis, 242. Commonly of rheumatic origin, 242. Chronic scleritis, 243. Complicated by involvement of the cornea, 213. Episcleritis, 244.

CHAPTER VII. page.

Diseases of the Iris.

Iritis, 246. Diagnostic signs and symptoms, 246. Etiology, 248. Consequences of neglected iritis, 250. Varieties of iritis,

250. Plastic, serous, and purulent iritis, 250. Rheumatic iritis,

251. Gonorrheal iritis, 251. " Trophic " nerve iritis, 252. Serous iritis, 252. Plastic iritis, 253. Syphilitic iritis, 254. Iritis condylomatosa, 255. Iritis gummosa, 255. Varieties of "trophic" nerve, or neuropathic, iritis, 255. Sympathetic iritis {sympathetic ophthalmitis), 256. Etiology, 256. Sympathetic irritation, 257. Iritis due to herpes zoster ophthalmicus, 259. Spongy iritis, 259. Chronic iritis, 260. Treatment of the different varieties of iritis, 260.

Diseases of the Ciliary Body.

Cyclitis, 268. Plastic cyclitis, 268. Purulent cyclitis, 268. Serous cyclitis, 268. Treatment of the several varieties of cyclitis, 269. Tumors of the ciliary body, 269. Often of malignant type, 269. An early diagnosis of the utmost importance, 269. Can be made only with the aid of the ophthalmoscope, 269.

Chapter VIII

Importance of an early diagnosis, 275. Consequences of failure to recognize glaucoma in its incipiency, 275. Hardening of the eyeball the essential feature of glaucoma, 275. Impairment of vision in glaucoma, 275. Primary glaucoma, 276. Secondary glaucoma, 276. Primary glaucoma extremely rare in persons under thirty years of age, 276. Secondary glaucoma may manifest itself at any period of life, 276. Varieties of primary glaucoma, 276. Buphthalmos, 276. Symptoms, subjective and objective, of inflammatory glaucoma, 277. Prodromal symptoms, 279. Factors which have to do with precipitating the acute exacerbations of glaucoma, 280. Consequences of unchecked inflammatory glaucoma, 281. Inexcusable mistakes made in diagnosticating glaucoma, 281. Glaucoma to be susspected whenever a painful inflammation of the eye, attended by impairment of sight, is encountered in an individual who has reached middle life, 281. Etiology of inflammatory glaucoma, 281. Accommodative strain an important factor in the causation of glaucoma, 285. Influence of mydriatics in precipitating an attack of glaucoma, when a predisposition to the disease exists, 285. Contraction of the visual field in glaucoma, 286. Treatment of inflammatory glaucoma, 287. Iridectomy the sov-

SYNOPSIS OF CONTENTS.

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ereign remedy, 287. The value of myotics in glaucoma, 288. Nature of their action, 288. Manner of their employment, 288. Dionin useful in conjunction with eserin, 289. Other non-operative measures useful in glaucoma, 289. Importance of correcting refractive and muscular anomalies in the incipient stage of glaucoma, 290. Simple glaucoma, 291. Symptoms and clinical history, 291. The ophthalmoscope and perimeter necessary to its diagnosis, 291. Treatment, 292. Iridectomy not the effective remedy it is in the inflammatory type of the disease, 292. Sympathectomy of doubtful value, 293. The systematic use of eserin, 293. The constitutional measures indicated, 293. Secondary glaucoma, 293. Etiology, 293. Symptoms and consequences, 294. Treatment, 294.

CHAPTER IX. Diseases of the Crystalline Lens and Vitreous Humor 2 95~337

Diseases of the Crystalline Lens.

Anatomy and histology of the lens, 295. Growth of the lens, 295. Changes which it undergoes with advancing age, 296. Significance of these changes, 297. With reference to presbyopia, 297. With reference to the development of cataract, 297. Nutrition of the lens, 297. Cataract, 297. Origin of the name, 297. Mistaken views of the Greeks and Romans as to the real nature of cataract, 297. Though encountered most frequently in old age, occurs at all periods of life, and may be of congenital origin, 298. Different classifications of cataract, 298. Senile or hard cataract, 298. Juvenile or soft cataract, 298. General cataract, 298. Partial cataracts, 298. Varieties of partial cataract, 298. Zonular cataract, 299. Anterior polar cataract, 299. Posterior polar cataract, 299. Congenital cataract, 299. Idiopathic cataract, 299. Complicated cataract, 299. Traumatic cataract, 299. Immature, mature, and hypermature cataract, 299. Secondary or capsular cataract, 299. General cataract, 299. Features common to the several varieties of general cataract, 299. Progressive impairment of vision in general cataract, 299. Characteristics of soft and of hard cataract, 301. " Second sight" a premonitory symptom of senile cataract, 302. Etiology of general cataract, 302. The development of cataract a degenerative, not an inflammatory, process, 302. Faulty nutrition of the lens the immediate cause of cataract, 302. This may be the result of a constitutional disorder, of senile decay, or of pathological changes in the eye itself, 302. Life-long accommodative strain a not unimportant factor in the causation of senile cataract, 303. Etiology of traumatic cataract, 303. Diagnosis of cataract, 304. Assistance afforded by oblique illumination and the instillation of a mydri-

SYNOPSIS OF CONTENTS.

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atic, 304. Determination of the maturity of cataract, 307. Treatment of cataract, 310. Improvement in vision in incipient cataract from the use of a mydriatic, 310. Discission, the procedure applicable to soft or juvenile cataract, 314. Extraction, applicable to hard or senile cataract, 315. Simple and combined extraction, 315. The success which attends extraction of cataract at the present day, 316. Conditions which militate against the success of the operation, 316. Linear extraction, 319. Suction extraction, 319. Partial Cataract, 320. Anterior polar cataract, 320. Pyramidal cataract, 321. Posterior polar cataract, 322. Zonular cataract, 324. Treatment of the several varieties of partial cataract, 325. Capsular cataract, 326. Etiology and treatment of capsular cataract, 326, 327. Dislocation of the crystalline lens, 327. May be complete or incomplete, 327. May be forward, into the anterior chamber, or backward, into the vitreous chamber, 327. Effect upon vision, 329. Treatment, 331.

Diseases of the Vitreous Humor.

Pathological" changes in the vitreous humor usually due to traumatism or to pre-existent disease of the uveal coat or retina, t,2>Z' Purulent panophthalmitis, 333. Treatment, 334. Fluidity of the vitreous humor, 334. Opacities of the vitreous humor, 334. M usees volitantes, 335. Hemorrhage into the vitreous humor, 336. Etiology, 336. Treatment, 337.

CHAPTER X. Diseases or the Choroid Coat, Retina, and Optic Nerve 338-387

General description of the symptoms indicative of disease of the choroid, retina, and optic nerve, which, when taken into account, enable the general practitioner, even without the aid of the ophthalmoscope, to reach an approximately accurate diagnosis, 338.

Diseases of the Choroid Coat.

Choroiditis, 340. May be plastic, purulent, or serous in type, 340. Purulent choroiditis, synonymous with purulent panophthalmitis, described in Chapter IX, 340. Serous choroiditis, synonymous with uveitis, considered in Chapter VII, 340. Plastic choroiditis, 340. Frequently dependent upon syphilis, 340. Syphilitic choroiditis, 340. Commonly involves the retina, 340. Runs a tedious course, 341. Both eyes usually affected, 341. If neglected may lead to loss of sight and to the development of cataract, 342. Choroiditis of high myopia, 342. Traumatic choroiditis, 342. Miliary choroido-retinitis, 343. A not uncommon consequence of accommodative strain, 343. Probably a factor,

SYNOPSIS OF CONTENTS.

of no mean importance, in the causation of glaucoma and of senile cataract, 344. Treatment of the several varieties of choroiditis. 345. Tumors of the choroid, 348.

Diseases of the Retina.

Retinitis, 348. Divisible into primary and secondary retinitis, 348. Also into serous and parenchymatous retinitis, 348. Retinitis unattended by photophobia or pain, 348. Impairment of vision the chief subjective symptom, 348. Causes of primary and of secondary retinitis, 349. Retinitis albuminurica, 349. Occurs in all forms of disease of the kidney accompanied by albuminuria, and not infrequently as an early symptom, 349. Also in the albuminuria of pregnancy and of scarlatina, 349. Nearly always bilateral, 349. Uremic amblyopia, 351. Treatment to be directed to the nephritis and to the general condition of the patient, 351. Diabetic retinitis, 351. Is always bilateral, 351. Not infrequently accompanied by cataract, and occasionally by iritis or glaucoma, 351. Prognosis unfavorable, 352. Treatment, 352. Leucocythemic retinitis, 352. Retinitis of pernicious anemia, 352. Syphilitic retinitis, 353. Energetic antisyphilitic treatment demanded, 353. Retinitis from exposure of the eyes to intense light, 353. Usually most marked in the macular region, 353. Treatment, 354. Retinitis pigmentosa, 354. Begins in early childhood, 354. May be congenital, 354. Often associated with congenital anomalies of the eye or of other organs, 354. Met with in the offspring of consanguineous marriages, 354. Night-blindness an early symptom, 355. Gradual contraction of visual field, with ultimate loss of central vision, 355. Treatment of little avail, 356. Embolism of the central artery of the retina, 357. Characterized by sudden loss of sight of the affected eye, 357. Striking ophthalmoscopic picture, exhibiting the "cherry -red spot at the macula," 357. Treatment, 358. Thrombosis of the central artery of the retina, 359. Probably the cause of the sudden loss of sight occasionally observed in acute anemia, 359. Symptoms and ophthalmoscopic picture similar to those observed in embolism, 359. Thrombosis of the central retinal vein, 359. Usually met with in elderly persons with organic heart disease or angiosclerosis, 359. May be caused by the extension of facial erysipelas to the orbit,

359. The ophthalmoscope shows enormous distention and great tortuosity of the retinal veins, with numerous hemorrhages scattered over the entire fundus, 360. Treatment of little avail,

360. Detachment of the retina, 360. Its etiology, 361. Far-fetched theories advanced to explain its occurrence unsatisfying,

361. Oftenest met with in high myopia, 361. May result from trauma, 361. Occurs in conjunction with intraocular growths,

362. Symptoms, 362. Annoying disturbance of vision to

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SYNOPSIS OF CONTENTS.

which it gives rise, 363. Prognosis most unfavorable, 363. Operative and non-operative treatment, 364. Glioma of the retina, 364. One of the most malignant of pathological new-growths, 364. Possibility of diagnosticating it by daylight inspection, with the assistance of a mydriatic, 365. Symptoms and course of the disease, 365. Enucleation of the eye at the earliest moment possible indicated, 366. But recurrence of the growth, especially in the brain, to be feared, 367. A disease of childhood, 365.

Diseases of the Optic Nerve.

Optic neuritis, 367. Divisible into retrobulbar neuritis and intraocular neuritis, 367. The latter again divisible into papillitis, or choked disc, and descending optic neuritis, 367. Etiology of descending optic neuritis and of choked disc, 368. Choked disc {papillitis), 370. Vision at first may be but slightly impaired, though pronounced fundus changes are present, 371. Usually dependent upon intracranial tumor, 371. Present in from eighty to ninety per cent, of intracranial new-growths, 371. Descending optic neuritis, 372. Fundus changes less marked than in choked disc, 372. Oftenest due to basilar meningitis attended by inflammation of the contiguous brain substance, 372. The prognosis in both choked disc and descending optic neuritis largely dependent upon the nature of the lesion which has led to their development, 372. Treatment, 373. Retrobulbar optic neuritis (orbital neuritis), 374. Occurs under two forms — Acute retrobulbar neuritis and chronic retrobulbar neuritis, or toxic amblyopia, 374, 375. In each the orbital portion of the nerve is first involved, and especially the papillo-macular fibers, 375. Acute retrobulbar neuritis, 374. Etiology, 374. Symptoms and course of the disease, 374, 375. Treatment, 375. Chronic retrobulbar neuritis (toxic amblyopia), 375. Etiology, 375. Symptoms, 375. Ophthalmoscopic changes observed,

377. Prognosis and treatment, 377. Quinin blindness, 377. Atrophy 0} the optic nerve, 3 78. Primary (simple) atrophy,

378. Nearly always bilateral, 379. Etiology, 379. Early symptoms, 379. Ophthalmoscopic signs, 379. Treatment usually of little avail, 381. Consecutive atrophy of the optic nerve (inflammatory atrophy), 381. Causes, 381. Subjective and objective symptoms, 381. Diagnosis to be established only by the ophthalmoscope, 381. Usually distinguishable from simple atrophy, 381. Prognosis not so unfavorable as in simple atrophy, 382. Treatment, 382. Hemianopsia, 383. Varieties, 383. Binasal and horizontal hemianopsia, uncommon, 384. Homonymous lateral hemianopsia and bitemporal hemianopsia more frequently encountered, 385. Explanation of the occurrence of the different varieties of hemian-

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opsia, 3S5. Homonymous lateral hemianopsia, 385. Causes, 385. Early and later symptoms, 385. Central vision seldom lost, 385. Transient hemianopsia, 386. Bitemporal hemianopsia, 386. Treatment, except in cases of syphilitic origin, usually without avail, 387.

CHAPTER XI. Anomalies of Refraction* and Accommodation 388-437

Anomalies of Refraction.

Prevalent misconceptions in regard to the measurement and correction of the refractive and muscular anomalies of the eyes,

388. No branch of ophthalmic practice more imperatively demands especial skill and training, 388. The harm which comes from the hap-hazard methods of the tyro who, after a few weeks' instruction in an "optical college," announces himself as an "ophthalmic optician," 388. Importance of the role errors of refraction play in the causation of ocular maladies,

389. Also in the production of maladies other than those of the eye, though, as to these, there has been much exaggeration. 389. Eye-strain a common cause of headache, neurasthenia, vertigo, disturbance of mental concentration, etc., 390. Observations upon some of the prevalent misconceptions regarding refractive errors, and concerning the indication for "glasses" and their influence upon sight, 391. Errors of refraction rarely "outgrown," and not to be gotten rid of by "rest of the eyes," massage, the application of drugs, etc., 391. Glasses not to be regarded as a dernier ressort, 391. Glasses do not "weaken the sight," as is popularly supposed, 391. No foundation for the belief that if glasses are worn in childhood a time may come when it will be impossible to obtain them of the required strength,

391. Glasses given not merely to sharpen vision but to relieve eve-strain, 391. Often demanded when there is normal acuteness of sight, 392. Exert a marked influence in checking the progress of myopia, 392. But it is not to be expected that they will "cure" the refractive fault for which they are prescribed, and only exceptionally does it happen that they can be put aside,

392. Not all eyes needing glasses make a direct appeal for their aid, 392. Not infrequently, when the remote consequences of eye-strain are pronounced, there may be no complaint of the eyes themselves, 392. Emmetropia, 393. Ametropia, 394. A general term denoting a departure from the normal in the optical construction of the eye, 394. Hvpermetropia (Jar-sightednesi). 395. The most prevalent form of ametropia, and nearly always of congenital origin, 395. Owing to an abnormal flatness of the eyeball, or a lack of refractive power in its lens system, the hyper-

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metropic eye is incapable of focusing upon the retina parallel rays of light, without an effort of accommodation, 395. Facultative and non- facultative hypermetropia, 395. Axial hypermetropia, 397. Curvature hypermetropia, 397. The ill consequences of hypermetropia, 398. The most important factor in the causation of convergent squint, 398. Asthenopia, headache, blepharitis marginalis, etc., common consequences of the eye strain to which it gives rise, 398. The ill effects of the higher grades of hypermetropia manifest themselves in early childhood,

398. The lower grades may cause no inconvenience until the presbyopic age is approached, 399. The whole treatment of hypermetropia comprised in the careful adjustment of glasses, 399. Whether these must be worn constantly, or only in near vision, will depend upon the degree of the refractive fault, the power of accommodation, and the relative strength of external and internal recti muscles,